Variable grain architecture for FPGA integrated circuits

• US 6,097,212 A
• Filed: 10/09/1997
• Issued: 08/01/2000
• Est. Priority Date: 10/09/1997
• Status: Expired due to Term

• Current Assignee: Lattice Semiconductor Corporation
• Original Assignee: Lattice Semiconductor Corporation
• Inventors: Agrawal, Om P., Sharpe-Geisler, Bradley A., Chang, Herman M., Tran, Giap H.
• Primary Examiner(s): Tokar, Michael
• Assistant Examiner(s): Chang, Daniel D.
• Application Number:
  US08/948,306
• Time in Patent Office: 1,027 Days
• Field of Search: 326/41, 326/40, 326/39, 326/38, 326/47, 326/101
• US Class Current: 326/41
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H03K 19/1737 using multiplexers H03K19/1738 takes precedence
• CPC Class Codes: H03K 19/17728 Reconfigurable logic blocks, e.g. lookup tables
• CPC Class Codes: H03K 19/17736 Structural details of routing resources
• CPC Class Codes: H03K 19/17748 Structural details of configuration resources
• CPC Class Codes: H03K 19/17752 for hot reconfiguration
• CPC Class Codes: H03K 19/17756 for partial configuration or partial reconfiguration
• CPC Class Codes: H03K 19/17792 for operating speed
• CPC Class Codes: H03K 19/17796 for physical disposition of blocks

Abstract

A Variable Grain Architecture is disclosed wherein Variable Grain Blocks (VGB'"'"'s) are wedged together in mirror opposition to one another to define super-VGB structures. The super-VGB structures are arranged as a matrix within an FPGA device. Each VGB includes progressive function synthesizing layers for forming more complex function signals by folding together less complex function signals of preceding layers. A function spawning layer containing a set of function spawning lookup tables (LUT'"'"'s) is provided near the periphery of the corresponding super-VGB structure. In one case, the function spawning layer is L-shaped and includes a symmetrical distribution of Configurable Building Blocks. A signal-acquiring layer interfaces with adjacent interconnect lines to acquire input terms for the LUT'"'"'s and controls. A decoding layer is interposed between the signal-acquiring layer and the function spawning layer for providing strapping and intercept functions. Each VGB has a common controls section, a wide-gating section and a carry-propagating section. Each super-VGB has a centrally-shared section of longline drivers that may be accessed from any of the constituent VGB'"'"'s. A diversified spectrum of interconnect lines, including 2xL, 4xL, 8xL and direct connect surround each super-VGB to provide different kinds of interconnect.

Claims

1. A field programmable gate array device comprising a plurality of Variable Grain Blocks (VGB'"'"'s) and a plural number, L of interconnect lines extending by the VGB'"'"'s, wherein each VGB includes:

(a) a signal acquisition layer having a first plurality, N of input multiplexers where N is less than L, said N input multiplexers being configurable for acquiring, from a subset of said L interconnect lines that are adjacent to that VGB, a respective first plurality of N input term signals;

(b) a function spawning layer having a second plurality, M of lookup tables (LUT'"'"'s), wherein each of the M LUT'"'"'s is a function spawning LUT that can be configurably coupled to receive a respective subset of input term signals from the first plurality of N input term signals and to responsively produce a respective first level function signal, and further wherein the second plurality of M spawning LUT'"'"'s have a total of at least N independent input terminals for consuming the acquired plurality of N input term signals;

(b.1) where in a first programmable mode of the VGB, the respective subsets of input term signals of respective ones of the function spawning LUT'"'"'s are mutually exclusive, and

(b.2) where in a second programmable mode of the VGB, the respective subsets of input term signals of respective ones of the function spawning LUT'"'"'s are not mutually exclusive; and

(c) progressive function synthesizing layers including first and second function synthesizing layers, wherein;

(c.1) said first function synthesizing layer is operatively coupled to the function spawning layer for combining the respective first level function signals of sets of two or more of the spawning LUTs to produce two or more second level function signals, each of said second level function signals being a function of more input term signals than is each of the correspondingly combined first level function signals used to produce that second level function signal, and

(c.2) said second function synthesizing layer is operatively coupled to the first function synthesizing layer for combining sets of two or more of the respective second level function signals to produce two or more third level function signals, each of said third level function signals being a function of more input term signals than is each of the correspondingly combined second level function signals used to produce that third level function signal.

2. A field programmable gate array device according to claim 1 wherein said progressive function synthesizing layers of each VGB further include a third function synthesizing layer, and wherein:

(c.3) said third function synthesizing layer is operatively coupled to the second function synthesizing layer for combining two or more of the respective third level function signals to produce one or more fourth level function signals, each of said fourth level function signals being a function of more input term signals than is each of the correspondingly combined third level function signals used to produce that fourth level function signal.

3. A field programmable gate array device according to claim 2 wherein within each VGB:

(b.1) the LUT'"'"'s of said function spawning layer include at least two 8-bit lookup tables whose outputs are combinable by said first function synthesizing layer.

4. A field programmable gate array device according to claim 2 wherein within each VGB:

(b.1a) the LUT'"'"'s of said function spawning layer include at least eight 8-bit lookup tables whose outputs are combinable by said first function synthesizing layer.

5. A field programmable gate array device according to claim 1 further comprising:

(d) a configurable decoding layer interposed between said signal acquisition layer and said function spawning layer, the decoding layer having configurable strapping means for;

(d.1) supporting said first programmable mode by providing a first configurable mode of the strapping means in which acquired input term signals are passed transparently from the signal acquisition layer to respective LUT'"'"'s of the function spawning layer such that said respective subsets of input term signals of the respective ones of the function spawning LUT'"'"'s can remain mutually exclusive; and

(d.2) supporting said second programmable mode by providing a second configurable mode of the strapping means in which a subset of acquired input terms are shared by plural LUT'"'"'s of the function spawning layer such that said respective subsets of input term signals of the respective ones of the function spawning LUT'"'"'s can be other than mutually exclusive.

6. A field programmable gate array device according to claim 5 wherein said decoding layer further comprises:

(d.3) configurable intercepting means which may be configured to intercept one or more of a subset of the acquired input term signals and prevent the intercepted input term signals from passing from the signal acquisition layer to respective LUT'"'"'s of the function spawning layer.

7. A field programmable gate array device comprising:

a plurality of super-VGB'"'"'s wherein each such super-VGB includes;

(a) a first variable grain block (VGB_-- A) having a respective first L-organization of plural Configurable Building Blocks (CBB'"'"'s); and

(b) a second variable grain block (VGB_-- B) having a respective second L-organization of CBB'"'"'s, the second L-organization being substantially mirror symmetrical with the first L-organization;

wherein each CBB (Configurable Building Block) comprises;

(a.1) a signal acquisition layer having acquisition means for acquiring, from an adjacent plurality of L interconnect lines, a respective first plurality, N of input term signals;

(a.2) a function spawning layer having a second plurality, M of lookup tables (LUT'"'"'s), wherein each of the M LUT'"'"'s is a function spawning LUT that can be configurably coupled to receive a respective subset of input term signals from the first plurality of N input term signals and to responsively produce a respective first level function signal, and further wherein the second plurality of M spawning LUT'"'"'s have a total of at least N independent input terminals for consuming the acquired plurality of N input term signals, and yet further wherein the respective subsets of input term signals can be mutually exclusive;

(a.3) a first function synthesizing layer that is operatively coupled to the function spawning layer for combining the respective first level function signals of sets of two or more of the spawning LUT'"'"'s to produce therefrom two or more second level function signals, where each of said second level function signals is a function of more input term signals than is each of the correspondingly combined first level function signals used to produce that second level function signal.

8. A field programmable gate array device according to claim 7 wherein each said super-VGB further comprises:

(c) a shared section having line driving resources shared by the first and second variable grain blocks.

9. A field programmable gate array device according to claim 8 wherein each super-VGB further includes:

(d) a third variable grain block (VGB_-- C) having a respective third L-organization of CBB'"'"'s, the third L-organization being substantially mirror symmetrical with each of the first and second L-organizations; and

(e) a fourth variable grain block (VGB_-- D) having a respective fourth L-organization of CBB'"'"'s, the fourth L-organization being substantially mirror symmetrical with each of the first, second and third L-organizations;

(c.1) wherein the line driving resources of the shared section are shared by the first through fourth programmable logic blocks.

10. A field programmable gate array device according to claim 7 wherein:

said plural Configurable Building Blocks of each said L-organization includes respective first through fourth CBB'"'"'s symmetrically distributed within the respective L-organization.

11. A field programmable gate array device comprising VGB-interconnecting lines each extending adjacent to a plurality of variable grain blocks (VGB'"'"'s), wherein each VGB has a plurality of configurable building elements (CBE'"'"'s) distributed within that VGB so as to be adjacent to at least a respective subset of plural ones of said VGB-interconnecting lines, wherein each of said VGB-interconnecting lines can provide interconnection between at least two VGB'"'"'s, and further wherein:

(a) each CBE has at least a first user-programmable lookup table (LUT) for generating a respective first output signal in accordance with a first user-defined lookup function f_a ( ), where f_a ( ) has a first plurality of input terms;

(b) each CBE includes input term acquisition means for selectively acquiring respective ones of said first plurality of input terms from respectively adjacent VGB-interconnecting lines, the respectively acquired ones of said first plurality of input terms being organized for dedicated consumption by that CBE when a programmably-defined, transparent decoding mode is in effect;

(c) each CBE of a given VGB further has passing therethrough, a decoding means interposed between the input term acquisition means and the LUT of that CBE, the decoding means being configurable to strap together inputs of plural ones of the LUT'"'"'s of plural CBE'"'"'s of the given VGB when a programmably-defined, decoding mode other than said transparent decoding mode is in effect; and

(d) each VGB includes first resource folding means for folding together resources found within individual CBE'"'"'s of that VGB.

12. A field programmable gate array device according to claim 11 wherein said first resource folding means has a fractal structure.

13. A field programmable gate array device according to claim 11 wherein each VGB has a plurality of at least 8, generally equivalent, CBE'"'"'s symmetrically distributed along a peripheral portion of the VGB.

14. A field programmable gate array device according to claim 11 wherein groups of VGB'"'"'s are arranged in mirror opposition to one another and wedged together such that VGB-interconnecting lines are not interposed between wedged together ones of the mirror-opposed VGB'"'"'s, wherein each group of wedged together VGB'"'"'s defines a corresponding super-VGB having an interior that is free of VGB-interconnecting lines and a periphery, and wherein each super-VGB has a plurality of at least 16 CBE'"'"'s distributed about its periphery.

15. A field programmable gate array device according to claim 14 wherein said VGB-interconnecting lines are provided in channels extending adjacent to said peripheral CBE'"'"'s and between super-VGB'"'"'s that are not wedged together and said channels of VGB-to-VGB interconnecting lines provide routing of input terms to destination ones of said VGB'"'"'s from source ones of said VGB'"'"'s.

85. The field programmable gate array device of claim 11 wherein:

(a.1) each CBE further has a second user-programmable LUT for generating a respective second output signal in accordance with a second user-defined lookup function f_b ( ), where f_b ( ) has a respective second plurality of input terms; and

(b.1) the respectively acquired ones of said plurality of input terms are organized at least as first and second subsets for dedicated and respective consumption by the first and second LUT'"'"'s of that CBE when the transparent decoding mode is in effect.

86. The field programmable gate array device of claim 85 wherein:

the configurable building elements (CBE'"'"'s) of each VGB are symmetrically distributed within that VGB.

87. The field programmable gate array device of claim 85 wherein:

groups of VGB'"'"'s are arranged in mirror opposition to one another and wedged together such that VGB-interconnecting lines are not interposed between wedged together ones of the mirror-opposed VGB'"'"'s;

each group of wedged together VGB'"'"'s defines a corresponding super-VGB having an interior that is free of VGB-interconnecting lines and a periphery; and

each super-VGB has a plurality of at least 8 CBE'"'"'s symmetrically distributed about its periphery.

88. The field programmable gate array device of claim 87 wherein:

(d.1) said first resource folding means in the mirror-opposed and wedged together VGB'"'"'s merge for thereby defining a second resource folding means for folding together resources found within the mirror-opposed and wedged together VGB'"'"'s.

89. The field programmable gate array device of claim 87 wherein:

one or more, shared line drivers are provided respectively for, and are each coupled to a respective interior of a respective one of the super-VGB'"'"'s such that output signals can be programmably routed through the one or more shared line drivers from either of the mirror-opposed and wedged together VGB'"'"'s of the respective super-VGB.

90. The field programmable gate array device of claim 11 and further comprising:

(e) second resource folding means for folding together resources found within individual VGB'"'"'s.

16. A method for configuring a Field Programmable Gate Array (FPGA) device to implement an original circuit design that has been partitioned into plural chunks, wherein the FPGA device comprises:

a plurality of variable grain blocks (VGB'"'"'s) wherein each VGB has an L-organized plurality of configurable building elements (CBE'"'"'s) symmetrically distributed along first and second, differently-directed legs of an L-organization, there being at least two essentially equivalent CBE'"'"'s in each of the first and second legs, with each CBE containing a configurable lookup table;

said method comprising the steps of;

(a) choosing to place a given chunk in one of the essentially equivalent first and second legs of a specific VGB based on the directivity of the chosen leg; and

(b) placing the given chunk in one of the essentially equivalent CBE'"'"'s of the chosen leg.

17. A method for configuring a FPGA device according to claim 16 further comprising the steps of:

(c) after placing the given chunk in one of the essentially equivalent CBE'"'"'s of the chosen leg, altering the placement of the given chunk to another of the essentially equivalent CBE'"'"'s of the chosen leg.

18. A method for configuring a FPGA device according to claim 16 further comprising the steps of:

(c) after placing the given chunk in one of the essentially equivalent CBE'"'"'s of the chosen leg, altering the placement of the given chunk to one of the essentially equivalent CBE'"'"'s of the unchosen leg.

20. A method for configuring a FPGA device according to claim 18 further comprising the steps of:

(c) after placing each given chunk in a correspondingly chosen one of said CBE'"'"'s, CBB'"'"'s, sets of paired-CBB'"'"'s, and sets of quadrupled-CBB'"'"'s, re-partitioning the original circuit so as to reduce the size of at least one chunk; and

(d) breaking down a larger member of said granulated entity group to form from the broken member two or more smaller members of said granulated entity group; and

(e) placing the size-reduced chunk in one of the smaller members of said granulated entity group which was formed by said step of breaking down.

19. A method for configuring a Field Programmable Gate Array (FPGA) device to implement an original circuit design that has been partitioned into plural chunks of different sizes, wherein the FPGA device comprises:

a plurality of variable grain blocks (VGB'"'"'s) wherein each VGB has an L-organized plurality of configurable building elements (CBE'"'"'s) symmetrically distributed along first and second legs of an L-organization, there being at least four essentially equivalent CBE'"'"'s in each of the first and second legs, where resources in pairs of CBE'"'"'s are combinable to provide larger capability resources in the form of configurable building blocks (CBB'"'"'s), and further where resources in pairs of CBB'"'"'s are combinable to provide larger capability resources in the form of sets of paired-CBB'"'"'s, and yet further where resources in quadruples of CBB'"'"'s are combinable to provide larger capability resources in the form of sets of quadrupled-CBB'"'"'s;

said method comprising the steps of;

(a) for each given one of the differently sized chunks, choosing a smallest nonconsumed member in the granulated entity group consisting of said CBE'"'"'s, CBB'"'"'s, sets of paired-CBB'"'"'s, and sets of quadrupled-CBB'"'"'s that can accommodate the given chunk; and

(b) placing each given chunk in a correspondingly chosen one of said CBE'"'"'s, CBB'"'"'s, sets of paired-CBB'"'"'s, and sets of quadrupled-CBB'"'"'s.

21. A method for configuring a FPGA device according to claim 19 wherein each CBE can provide any desired function of up to 3 independent input terms, each CBB can provide any desired function of up to 4 independent input terms, each set of paired-CBB'"'"'s can provide any desired function of up to 5 independent input terms, and each set of quadrupled-CBB'"'"'s can provide any desired function of up to 6 independent input terms.

22. A method for configuring a FPGA device according to claim 21 wherein each VGB includes a decoding means that is configurable to strap together input resources of plural ones of the CBE'"'"'s when a non-transparent decoding mode is in effect, said method further comprising the step of:

(c) using the decoding means within a given VGB to strap together one or more of the input resources that receive the 3 independent input terms, the strapped together input resources being ones belonging to two or more CBE'"'"'s, said strapping causing the strapped-together CBE'"'"'s to operate in parallel on a common one or more of the input terms.

23. A field programmable gate array device comprising a matrix of Super Variable Grain Blocks (super-VGB'"'"'s) and a plural number of interconnect lines extending about the super-VGB'"'"'s, said interconnect lines providing signal interconnection between the super-VGB'"'"'s, wherein each super-VGB includes:

(a) a plurality of Variable Grain Blocks (VGB'"'"'s), where said VGB'"'"'s of the super-VGB are arranged in mirror opposition to one another and wedged together such that said interconnect lines are not interposed between wedged together ones of the mirror-opposed VGB'"'"'s, and wherein each of the wedged-together VGB'"'"'s comprises;

(a.1) a signal-acquisition layer positioned adjacent to a set of the interconnect lines and coupled to said set of interconnect lines for extracting from said set, a first smaller subset of input term signals;

(a.2) a function spawning layer capable of receiving each of the extracted input term signals and producing a first plurality of first level function signals in response to the received input term signals;

(a.3) a decoding layer interposed between the signal-acquisition layer and the function spawning layer, said decoding layer being configurable to, in a first mode pass each of the extracted input term signals for receipt by the function spawning layer, and in a second mode intercept at least one of the extracted input term signals and substitute therefor another of the extracted input term signals for receipt by the function spawning layer;

(a.4) one or more function synthesis layers, coupled to the function spawning layer, for synthesizing from the spawned first plurality of first level function signals, a corresponding one or more higher level function signals; and

(a.5) a synthesis forwarding means coupled to receive the first plurality of first level function signals and the one or more higher level function signals and to output as a shareable signal a configuration-selected one of the received function signals.

24. A field programmable gate array device according to claim 23 and further wherein each super-VGB comprises:

(b) a shared logic section coupled to receive at least the shareable signals of two VGB'"'"'s and to dynamically select one of the at least two shareable signals for output from the super-VGB.

25. A field programmable gate array device according to claim 24 wherein:

said interconnect lines extending about the super-VGB'"'"'s include 2xL lines that each continuously extends approximately a distance covered by, but not substantially beyond, a combination of two wedged-together VGB'"'"'s;

said interconnect lines surrounding the super-VGB'"'"'s include MaxL lines that each continuously extends approximately a distance covered by said matrix of super-VGB'"'"'s;

(b.1) the shared logic section of each super-VGB includes one or more MaxL line drivers for outputting a selected shareable signal onto a corresponding MaxL line; and

(a.5a) the synthesis forwarding means of each VGB includes a 2xL line driver for outputting a selected one of the received function signals onto a corresponding 2xL line.

26. A field programmable gate array device according to claim 24 wherein:

(a.1a) said signal-acquisition layer is further for extracting from said set of interconnect lines, a second smaller subset of control signals;

(a.6) each of the wedged-together VGB'"'"'s further comprises a common controls section coupled to receive said subset of control signals and to produce therefrom a dynamic selection signal; and

(b.1) said shared logic section is coupled to receive the dynamic selection signal and to use the dynamic selection signal for dynamically selecting one of the at least two shareable signals.

27. A field programmable gate array device according to claim 26 wherein:

(b.1a) said shared logic section includes a three state drive amplifier having an output enable terminal, a data input terminal and an output terminal that can be placed in a high impedance mode;

(b.1b) said shared logic section further includes a selection multiplexer that is coupled to receive as data inputs, said at least two shareable signals and that is further coupled to output a selected one of the at least two shareable signals to the data input terminal of the three state drive amplifier, and that is yet further coupled to receive as a selection control, said dynamic selection signal.

28. A FPGA device according to claim 23 wherein said plural number of interconnect lines extending about the super-VGB'"'"'s includes groups each with a first plural number of interconnect lines extending adjacent to a corresponding first side of each super-VGB, and further wherein:

(a.1a) said signal-acquisition layer within each VGB that is adjacent to a given group of L1 interconnect lines includes a second plural number N of input term acquiring multiplexers, where a first subset of the N multiplexers is adjacent to the corresponding first side and each respective one of the first subset of input term acquiring multiplexers is configurable to extract a respective input term signal from a configuration defined one of a respective subset of M1 of the L1 adjacent interconnect lines, where M1 is an integer that causes the ratio L1/M1 to be about 2 or greater than 2.

29. A FPGA device according to claim 28 wherein M1 is an integer that causes the ratio L1/M1 to be equal to about 3.

30. A FPGA device according to claim 28 wherein:

(a.1a'"'"') the first subset of the N multiplexers in each VGB that is adjacent to a given group of L1 interconnect lines defines about half of said N multiplexers, and (a.1a") the remainder of said N multiplexers is adjacent to a corresponding second side of the super-VGB, the second side having a second plural number L2 of interconnect lines extending adjacent thereto, and wherein each respective one of the second subset of input term acquiring multiplexers is configurable to extract a respective input term signal from a configuration defined one of a respective subset of M2 of the L2 adjacent interconnect lines, where M2 is an integer that causes the ratio L2/M2 to be about 2 or greater than 2.

31. A FPGA device according to claim 23 wherein said plural number of interconnect lines extending about the super-VGB'"'"'s includes groups each with a first plural number L of interconnect lines extending adjacent to a corresponding side of each super-VGB, and further wherein:

(a.1a) said signal-acquisition layer within each VGB includes a plural number N of input term acquiring multiplexers, each respective one of the input term acquiring multiplexers being configurable to extract a respective input term signal from a configuration defined one of the group of L interconnect lines adjacent to that multiplexer, where the N input term acquiring multiplexers of each VGB are dividable into at least two redundant sets, with each such set of input term acquiring multiplexers being configurable to extract an essentially equivalent subset of input term signals from configuration defined ones of the L interconnect lines adjacent to that redundant set of input term acquiring multiplexers.

32. A FPGA device according to claim 31 wherein the N input term acquiring multiplexers of each VGB are dividable into at least four redundant subsets, with each such subset of input term acquiring multiplexers being configurable to extract a same number of input term signals from like ones of adjacent interconnect lines, where each corresponding four or more ones of like, adjacent interconnect lines has a substantially same continuous length.

33. A FPGA device according to claim 28 wherein:

(a.2a) said function spawning layer within each VGB that is adjacent to a given group of L1 interconnect lines includes a third plural number, N/P of substantially identical lookup tables (LUT'"'"'s) with each such LUT having a fourth plural number, P of data input terminals, P being such that N/P is an integer greater than 1.

34. A FPGA device according to claim 33 wherein:

(a.2a'"'"') N is at least 12 and P is at least 3.

35. A FPGA device according to claim 34 wherein:

(a.2a") N is at least 24 and P is 3.

36. A field programmable gate array (FPGA) device comprising a plurality of Super Variable Grain Blocks (super-VGB'"'"'s), wherein each super-VGB includes:

(a) a plurality of Variable Grain Blocks (VGB'"'"'s), with each of the VGB'"'"'s having a plurality of Configurable Building Blocks (CBB'"'"'s), wherein each of the CBB'"'"'s comprises;

(a.1) a first plurality, M of programmable lookup tables (LUT'"'"'s) each having a second plurality, N of input-term receiving terminals and an output terminal for producing a LUT output signal representative of a function of as many as N input term signals that are suppliable to the input-term receiving terminals of the LUT;

(a.2) a first level selection multiplexer having a first level output, a plurality of M data input terminals each coupled to an output terminal of a respective one of the M LUT'"'"'s, and further having one or more selection control terminals for receiving a first level selection signal;

(a.3) a configurable selection controller for producing said first level selection signal, the configurable selection controller being configurable into a dynamic selection mode wherein the first level selection signal can dynamically select one of the signals of the M data input terminals for output from the first selection multiplexer during a run-time operation of said FPGA device, and the configurable selection controller being configurable into a static selection mode wherein a predefined one of the M data input terminals is consistently selected for output from the first level selection multiplexer during a run-time operation of said FPGA device; and

(a.4) a configurable decoding circuit, operatively coupled to the input-term receiving terminals of the M LUT'"'"'s and to the selection controller, said decoding circuit being coupled to receive at least as many as M times N independent input term signals,

(a.4a) said decoding circuit being configurable into a first mode wherein the M times N input term signals pass through the decoding circuit each to a corresponding one of the M times N input-term receiving terminals of said M lookup tables,

(a.4b) said decoding circuit being further configurable into a second mode wherein less than the M times N of the received input term signals pass through the decoding circuit each to a corresponding one of a first subset of the M times N input-term receiving terminals of said M LUT'"'"'s and wherein remaining ones of the M times N input-term receiving terminals are strapped by the decoding circuit to others of the input-term receiving terminals such that each so-strapped terminal receives a respective copy of one of the passed-through input term signals.

37. A FPGA device according to claim 36 wherein:

(a.4c) said decoding circuit is further configurable into a third mode wherein at least one of the M times N received input term signals is intercepted such that the intercepted input term signal does not pass through the decoding circuit to a corresponding one of the input-term receiving terminals but is instead coupled to the selection controller for producing, when the dynamic selection mode of the selection controller is active, said first level selection signal; and

(a.4d) the second and third modes of the decoding circuit are not mutually exclusive.

38. A FPGA device according to claim 37 wherein each CBB further comprises:

(a.5) a signal chaining circuit, operatively coupled to the output of the first level selection multiplexer, to at least one of the LUT'"'"'s, and to the selection controller, the signal chaining circuit including;

(a.5a) sum producing means for producing at an output thereof a sum signal from a carry-in signal supplied to a carry-in input of the sum producing means, the sum producing means being coupled to respond to a first chaining control signal produced from the output of the first level selection multiplexer; and

(a.5b) next-carry producing means having a next-carry output for producing a next-carry signal from the supplied carry-in signal, the next-carry bit producing means being coupled to respond to a second chaining control signal produced from the output of the at least one LUT, wherein the produced next-carry signal is of a logic polarity opposite to that of the supplied carry-in signal.

39. A FPGA device according to claim 38 wherein the next-carry output of a first of the CBB'"'"'s in a first VGB is directly connected to the carry-in input of a second of the CBB'"'"'s in said first VGB.

40. A FPGA device according to claim 39 wherein for each given CBB:

(a.5b2) the next-carry producing means includes a forced state circuit that is operatively coupled to the configurable selection controller such that activation of the dynamic selection mode causes the forced state circuit to output a static chain-mode signal that is opposite to a predefined state of the carry-in signal, said predefined state of the carry-in signal being one that indicates an unbroken-chain condition for a sequential chain of one or more, preceding signal chaining circuits that supply the carry-in signal to the signal chaining circuit of the given CBB.

41. A FPGA device according to claim 40 wherein said activation of the dynamic selection mode applies a logic `0` to an input of the forced state circuit and causes the forced state circuit to output said static chain-mode signal as representing a logic `1`, and wherein the predefined state of the carry-in signal is a logic `0`.

42. A FPGA device according to claim 38 wherein the next-carry output of a first of the CBB'"'"'s in a first VGB is directly connected to the carry-in input of a second of the CBB'"'"'s in a second VGB.

43. A FPGA device according to claim 38 wherein the next-carry output of a first of the CBB'"'"'s in a first super-VGB is directly connected to the carry-in input of a second of the CBB'"'"'s in a second super-VGB, there being an interconnect channel interposed between said first and second super-VGB'"'"'s.

44. A FPGA device according to claim 38 wherein each CBB further comprises:

(a.5) a Configurable Sequential Element (CSE), the CSE including;

(a.5a) a plurality of CSE input terminals respectively coupled to the output of the first level selection multiplexer, to the output of at least one of the LUT'"'"'s, and to the output of the sum producing means;

(a.5b) a plurality of output drivers;

(a.5c) configurable routing means, coupled for receiving result signals from the plurality of CSE input terminals and for routing the received result signals or derivatives thereof to configuration-defined ones of the plurality of CSE output drivers.

45. A FPGA device according to claim 44 wherein:

(a.5b1) said plurality of output drivers includes at least two differently-powered output drivers.

46. A FPGA device according to claim 45 wherein:

(a.5b2) said plurality of output drivers includes at least three differently-powered output drivers.

47. A FPGA device according to claim 45 wherein said at least two differently-powered output drivers of each CBB of a given VGB include:

(a.5b2) a direct connect output driver having an input for receiving from the configurable routing means, a configuration-defined one of the received result signals or derivatives thereof, and further having an output that is directly coupled to one or more others of said CBB'"'"'s in others of said VGB'"'"'s.

48. A FPGA device according to claim 45 wherein said at least two differently-powered output drivers of each CBB of a given VGB include:

(a.5b2) a feedback output driver for receiving from the configurable routing means, a configuration-defined one of the received result signals or derivatives thereof, and further having an output that is directly coupled to one or more others of said CBB'"'"'s in the same given VGB.

49. A FPGA device according to claim 45 wherein said at least two differently-powered output drivers of each CBB of a given VGB include:

(a.5b2) an indirect output driver having an input for receiving from the configurable routing means, a configuration-defined one of the received result signals or derivatives thereof, and further having one or more outputs that are indirectly couplable to one or more others of said CBB'"'"'s in others of said VGB'"'"'s.

50. A FPGA device according to claim 44 wherein:

(a.5d) each CSE further includes a storage element for storing a configuration-defined one of the received result signals and for outputting the stored signal as a corresponding derivative of the configuration-defined result signal; and

(a.5c1) said configurable routing means includes a storage bypass multiplexer for outputting a configuration-defined one of the signal stored by the storage element or the corresponding one of the received result signals.

51. A FPGA device according to claim 44 wherein:

(a.5d) each CSE further includes a storage element for storing a configuration-defined one of the received result signals and for outputting the stored signal as a corresponding derivative of the configuration-defined result signal; and

(a.5c1) said configurable routing means includes a result signal selecting multiplexer coupled to receive said result signals from the plurality of CSE input terminals and to output a configuration-defined one of the result signals to said storage element.

52. A FPGA device according to claim 37 wherein each VGB further comprises:

(a.5) a second-level selection multiplexer having a second-level output, a plurality of data input terminals coupled to respective first-level outputs of respective ones of the first-level selection multiplexers and further having one or more second-level selection control terminals for receiving a second-level selection signal; and

(a.6) a second-level selection control circuit, operatively coupled to the one or more second-level selection control terminals, the second-level selection control circuit being configurable to supply an intercepted one of the M times N received input term signals from the decoding circuit as said second-level selection signal.

53. A FPGA device according to claim 52 wherein each VGB further comprises:

(a.7) a third-level selection multiplexer having a third-level output, a plurality of data input terminals coupled to respective second-level outputs of respective ones of the second-level selection multiplexers and further having one or more third-level selection control terminals for receiving a third-level selection signal; and

(a.8) a third-level selection control circuit, operatively coupled to the one or more third-level selection control terminals, the third-level selection control circuit being configurable to supply an intercepted one of the M times N received input term signals from the decoding circuit as said third-level selection signal.

54. A FPGA device according to claim 36 wherein each VGB contains at least 4 CBB'"'"'s distributed so as to define an L-organized section of CBB'"'"'s, wherein the at least 4 CBB'"'"'s are symmetrically distributed about said L-organized section.

55. A FPGA device according to claim 54 wherein each super-VGB contains at least 4 VGB'"'"'s arranged in mirror opposition to one another.

56. A FPGA device according to claim 36 wherein M is equal to 2 and N is equal to 3.

57. A field programmable gate array (FPGA) device comprising linear arrays of Super Variable Grain Blocks (super-VGB'"'"'s) and a plural number of interconnect lines each extending adjacent to a respective one of the linear arrays of super-VGB'"'"'s, said interconnect lines constituting adjacent interconnect lines (AIL'"'"'s) and providing signal interconnection between the super-VGB'"'"'s, wherein each super-VGB includes:

(a) a plurality of Variable Grain Blocks (VGB'"'"'s), with each of the VGB'"'"'s having a plurality of Configurable Building Blocks (CBB'"'"'s), wherein each of the CBB'"'"'s comprises;

(a.1) a first plurality, M of substantially identical lookup tables (LUT'"'"'s) each having a second plurality, N of input-term receiving terminals and an output terminal;

(a.2) a first dynamic selection multiplexer having plural data input terminals each coupled to an output terminal of a respective one of the M LUT'"'"'s, and further having one or more selection control terminals for receiving a first selection signal that can be configured to dynamically select one of the signals of the plural data input terminals for output from the first dynamic selection multiplexer during a run-time operation of said FPGA device;

(a.3) a configurable decoding circuit, operatively coupled to the input-term receiving terminals of the M LUT'"'"'s and to the selection controller, said decoding circuit being coupled to receive at least as many as M times N independent input term signals,

(a.3a) said decoding circuit being configurable into a first mode wherein the M times N input term signals pass through the decoding circuit each to a corresponding one of the M times N input-term receiving terminals of said M lookup tables,

(a.3b) said decoding circuit being further configurable into a second mode wherein less than the M times N of the received input term signals pass through the decoding circuit each to a corresponding one of a first subset of the M times N input-term receiving terminals of said M LUT'"'"'s and wherein remaining ones of the M times N input-term receiving terminals are strapped by the decoding circuit to others of the input-term receiving terminals such that each so-strapped terminal receives a respective copy of one of the passed-through input term signals; and

(a.4) a plurality of signal-acquiring multiplexers each coupled to receive inputs from a subset of said adjacent interconnect lines (AIL'"'"'s) and to supply a configuration-defined one of the received inputs to said decoding circuit as a respective input term signal.

58. A field programmable gate array (FPGA) device comprising a core composed of joined-together tiles, wherein:

(a) each tile has a plurality of Variable Grain Blocks (VGB'"'"'s) and each tile is surrounded by interconnect lines, where the tile-surrounding lines include 2xL lines and passing-through portions of longer-length lines;

(b) each VGB includes;

(b.1) a plurality of configurable building elements (CBE'"'"'s) with each CBE comprising;

(b.1a) signal acquiring resources for acquiring signals from adjacent interconnect lines; and

(b.1b) a configurable lookup table (LUT); and

(b.2) combining means for selectively folding together one or more of the signal acquiring resources and LUT'"'"'s of a respective two or more CBE'"'"'s within the VGB so as to define a combined unit having larger signal acquiring or lookup capabilities;

where the passing-through portions of longer-length lines of one tile extend into the passing-through portions of longer-length lines of one or more adjacent tiles;

where each 2xL line is continuous over a first span of about but no more than one tile;

where each longer-length line is continuous over a second span that is substantially larger than the first span.

59. A field programmable gate array (FPGA) device comprising a plurality of Super Variable Grain Blocks (super-VGB'"'"'s) and adjacent interconnect lines for providing interconnection between said super-VGB'"'"'s, wherein each super-VGB includes:

(a) a plurality of Variable Grain Blocks (VGB'"'"'s), with each of the VGB'"'"'s having a plurality of Configurable Building Blocks (CBB'"'"'s), wherein each of the CBB'"'"'s comprises;

(a.1) a first plurality of signal-acquiring multiplexers each coupled to receive inputs from a respective first subset of said adjacent interconnect lines (AIL'"'"'s) and to supply a configuration-defined one of the received inputs as a respective input term signal;

(a.2) a second plurality of signal-acquiring multiplexers each coupled to receive inputs from a respective second subset of said adjacent interconnect lines (AIL'"'"'s) and to supply a configuration-defined one of the received inputs as a respective control signal;

(a.3) a third plurality, M of programmable lookup tables (LUT'"'"'s) operatively coupled to said first plurality of signal-acquiring multiplexers, each LUT having a fourth plurality, N of input-term receiving terminals and an output terminal for producing a LUT output signal representative of a function of as many as N input term signals that are suppliable to the input-term receiving terminals of the LUT; and

wherein each VGB further comprises;

(b) a common controls producing section operatively coupled to said second plurality of signal-acquiring multiplexers of each of the CBB'"'"'s in the VGB;

the common controls producing section producing common control signals from configuration-defined ones of control signals output by said second pluralities of signal-acquiring multiplexers, said common control signals each being supplied to each of the CBB'"'"'s in the VGB.

60. A FPGA device according to claim 59 wherein each CBB further comprises:

(a.4) a Configurable Sequential Element (CSE) having controllable register means operatively coupled to receive and store a result signal derived from an output of one or more of said M programmable lookup tables of the CBB, the register means of said CSE further being operatively coupled to the common controls producing section for receiving and responding to one or more of said common control signals.

61. A FPGA device according to claim 59 wherein each VGB further comprises:

(c) a carry propagating section operatively coupled to directly receive a carry-input signal from an adjacent VGB and to receive addition control signals and to responsively produce a carry-output signal.

62. A FPGA device according to claim 59 wherein each super-VGB has a shared section and wherein each VGB further comprises:

(c) a shared logic section operatively coupled to the shared section of the encompassing super-VGB and further coupled to the CBB'"'"'s of the VGB, for producing shared drive signals and supplying said shared drive signals to the shared section of the encompassing super-VGB.

63. A multiplexer implementing method applicable to a field programmable gate array (FPGA) device having one or more Configurable Building Blocks (CBB'"'"'s) wherein each of the CBB'"'"'s comprises:

(0.1) a first plurality, M of substantially identical lookup tables (LUT'"'"'s) each having a second plurality, N of input-term receiving terminals and an output terminal, wherein N is 3 or greater and the N input-term receiving terminals of each said LUT can receive a respective and mutually exclusive subset of N input-term signals; and

(0.2) a first dynamic selection multiplexer having plural data input terminals each coupled to an output terminal of a respective one of the M LUT'"'"'s, and further having one or more selection control terminals for receiving a first selection signal that can be configured to either dynamically select one of the signals of the plural data input terminals for output from the first dynamic selection multiplexer during a run-time operation of said FPGA device or to statically select without dependence on one of the N input signals, one of the signals of the plural data input terminals for output from the first dynamic selection multiplexer during said run-time operation;

said method comprising the steps of;

(a) configuring two or more of the M lookup tables to each function as a 2-to-1 multiplexer having 2 input term receiving terminals, an output terminal, and one dynamic selection receiving terminal;

(b) configurably strapping together the dynamic selection receiving terminals of two or more of said 2-to-1 multiplexers to receive a first dynamic selection signal; and

(c) configuring the dynamic selection multiplexer to receive a second dynamic selection signal and to responsively and dynamically select and to correspondingly output a signal from the output terminal of one of said two or more 2-to-1 multiplexers whose dynamic selection receiving terminals are strapped together.

64. A data steering method applicable to a field programmable gate array (FPGA) device having interconnect channels and one or more Configurable Building Blocks (CBB'"'"'s) wherein each of the CBB'"'"'s comprises:

(0.1) a first plurality, M of substantially identical lookup tables (LUT'"'"'s) each having a second plurality, N of input-term receiving terminals and an output terminal, N being 3 or greater; and

(0.2) a Configurable Sequential Element (CSE) having plural data input terminals operatively coupled to receive results signals that are either derived from or supplied from output terminals of a respective two or more of the M LUT'"'"'s, and further having one or more line drive terminals for outputting selected ones of the received results signals onto interconnect lines of said FPGA device;

said method comprising the steps of;

(a) configuring one or more of the M lookup tables to each function as a 2-to-1 multiplexer having 2 input term receiving terminals, an output terminal, and one dynamic selection receiving terminal;

(b) supplying a first bus bit from a first bus having plural bits to a first input term receiving terminal of a first of said M lookup tables that is configured to function as a 2-to-1 multiplexer;

(c) supplying a second bus bit from a second bus having plural bits to a second input term receiving terminal of said first of the M lookup tables that is configured to function as a 2-to-1 multiplexer;

(d) supplying a bus selection signal to the dynamic selection receiving terminal of said first of the M lookup tables; and

(e) coupling a dynamically selected one of the first and second bus bits from the output terminal of said first of the M lookup tables that is configured to function as a 2-to-1 multiplexer to an input of said CSE.

65. A data steering method according to claim 64 wherein there are at least two of the M lookup tables each configured to function as a 2-to-1 multiplexer, said method comprising the step of:

(f) programmably placing the at least two 2-to-1 multiplexers in LUT'"'"'s that are adjacent to a same interconnect channel.

66. An input signal sharing method applicable to a field programmable gate array (FPGA) device having interconnect channels and two or more Configurable Building Blocks (CBB'"'"'s) wherein each of the CBB'"'"'s comprises:

(0.1) a first plurality, M of substantially identical lookup tables (LUT'"'"'s) each having a second plurality, N of input-term receiving terminals and an output terminal, N being 3 or greater; and

(0.2) a third plurality, M times N, of configurable input multiplexers for acquiring input term signals from adjacent ones of the interconnect channels; and

(0.3) a configurable decoding circuit, operatively coupled to the input-term receiving terminals of the M LUT'"'"'s and to the third plurality of M times N configurable input multiplexers, said decoding circuit being coupled to receive at least as many as M times N independent input term signals from the configurable input multiplexers,

(0.3a) said decoding circuit being configurable into a first mode wherein the M times N input term signals pass through the decoding circuit each to a corresponding one of the M times N input-term receiving terminals of said M lookup tables,

(0.3b) said decoding circuit being further configurable into a second mode wherein less than the M times N of the received input term signals pass through the decoding circuit each to a corresponding one of a first subset of the M times N input-term receiving terminals of said M LUT'"'"'s and wherein remaining ones of the M times N input-term receiving terminals are strapped by the decoding circuit to others of the input-term receiving terminals such that each so-strapped terminal receives a respective copy of one of the passed-through input term signals;

said method comprising the step of;

(a) configuring the decoding circuit into said second mode so as to thereby cause two or more of the M LUT'"'"'s to share at least one input signal.

67. An input signal sharing method according to claim 66 further comprising the step of:

(b) configuring at least two of the LUT'"'"'s to function as dynamic multiplexers each having at least two input term receiving terminals, an output terminal, and one dynamic selection receiving terminal;

(a.1) wherein the shared at least one input signal is a dynamic selection signal applied to the dynamic selection receiving terminals of the at least two of the LUT'"'"'s.

68. An input signal sharing method applicable to a field programmable gate array (FPGA) device having interconnect channels and two or more Variable Grain Blocks (VGB'"'"'s), where each VGB comprises two or more Configurable Building Blocks (CBB'"'"'s) and wherein each of the CBB'"'"'s comprises:

(0.1) a first plurality, M of substantially identical lookup tables (LUT'"'"'s) each having a second plurality, N of input-term receiving terminals and an output terminal, N being 3 or greater; and

(0.2) a third plurality, M times N, of configurable input multiplexers for acquiring input term signals from adjacent ones of the interconnect channels; and

wherein each VGB further comprises

(0.3) a configurable decoding circuit, operatively coupled to the input-term receiving terminals of the M LUT'"'"'s in each of the at least two CBB'"'"'s and to the third plurality of M times N configurable input multiplexers in each of the at least two CBB'"'"'s, said decoding circuit being coupled to receive at least as many as the M times N independent input term signals in each of the at least two CBB'"'"'s from respective ones of the configurable input multiplexers,

(0.3a) said decoding circuit being configurable into a first mode wherein the M times N input term signals in each of the at least two CBB'"'"'s pass through the decoding circuit each to a corresponding one of the M times N input-term receiving terminals of said M lookup tables in each of the at least two CBB'"'"'s,

(0.3b) said decoding circuit being further configurable into a second mode wherein less than the M times N of the received input term signals pass through the decoding circuit each to a corresponding one of a first subset of the M times N input-term receiving terminals of said M LUT'"'"'s in each of the at least two CBB'"'"'s and wherein remaining ones of the M times N input-term receiving terminals are strapped by the decoding circuit to others of the input-term receiving terminals such that each so-strapped terminal receives a respective copy of one of the passed-through input term signals;

said method comprising the step of;

(a) configuring the decoding circuit into said second mode so as to thereby cause two or more LUT'"'"'s of different CBB'"'"'s to share at least one input signal.

69. An input signal sharing method according to claim 68 further comprising the step of:

(b) coupling the shared at least one input signal by way of an adjacent interconnect channel so as to thereby cause two or more LUT'"'"'s of different VGB'"'"'s to share the at least one input signal.

70. A LUT cascading method applicable to a field programmable gate array (FPGA) device having two or more Variable Grain Blocks (VGB'"'"'s) and interconnect channels for interconnecting the VGB'"'"'s, where each VGB comprises two or more Configurable Building Blocks (CBB'"'"'s) and wherein each of the CBB'"'"'s comprises:

(0.1) a first plurality, M of substantially identical lookup tables (LUT'"'"'s) each having a second plurality, N of input-term receiving terminals and an output terminal, N being 3 or greater; and

(0.2) a third plurality, M times N, of configurable input multiplexers for acquiring input term signals from adjacent ones of the interconnect channels and in one configurable mode, supplying the acquired M times N input term signals to respective ones of the M times N input-term receiving terminals of the first plurality of LUT'"'"'s; and

wherein each given VGB further comprises

(0.3) feedback lines providing coupling only within the given VGB between outputs of CBB'"'"'s within the given VGB and respective input multiplexers of the CBB'"'"'s within the given VGB;

said method comprising the step of;

(a) using the feedback lines of a given VGB to cascade the output of an LUT in a first CBB within the given VGB to an input multiplexer of another of the CBB'"'"'s within the given VGB.

71. A method for configuring an FPGA having multiple lookup tables (LUT'"'"'s) where each LUT has at least three address inputs and a respective LUT output, wherein respective LUT output signals of the respective LUT outputs of each respective one of said multiple lookup tables are each independently and programmably couplable to an address input of another of said multiple lookup tables without reliance on a state of another input of the respective LUT, where said FPGA further has a dynamically-controllable first multiplexer capable of dynamically selecting for output therefrom, a signal of one of at least two respective LUT outputs from a corresponding at least first and second of said multiple LUT'"'"'s, wherein said FPGA further has a dynamism disabling circuit that is programmable to disable the dynamic-controllability of the first multiplexer;

said method comprising the steps of;

(a) configuring said second LUT to implement a respective dynamically-controllable second multiplexer having at least one dynamically-controllable select terminal and at least two data input terminals such that the second multiplexer is capable of dynamically selecting for output therefrom, a data signal of one of its said at least two data input terminals in response to a select-control signal supplied to its at least one dynamically-controllable select terminal;

(b1) configuring the dynamically-controllable first multiplexer to select as its output at least the respective LUT output of said first LUT; and

(b2) configuring the dynamism disabling circuit to be in a desired state of either disabling the dynamic-controllability of the first multiplexer or not disabling the dynamic-controllability of the first multiplexer.

72. The method of claim 71 further comprising the step of:

(c) configuring said first LUT to implement a respective dynamically-controllable third multiplexer having at least one dynamically-controllable select terminal and at least two data input terminals such that the third multiplexer is capable of dynamically selecting for output therefrom, a data signal of one of its said at least two data input terminals in response to a select-control signal supplied to its at least one dynamically-controllable select terminal.

73. The method of claim 72 further comprising the step of:

(d) coupling the dynamically-controllable select terminals of the dynamically-controllable second and third multiplexers to respond to a common select-controlling signal.

74. The method of claim 71 wherein said multiple lookup tables define an overall repeated circuit pattern within the FPGA and each said LUT has no more address inputs than said three address inputs such that implementing a 2-to-1 dynamically-controllable multiplexer in each said LUT exhausts the address inputs of the LUT.

75. A method for configuring a Field Programmable Gate Array (FPGA) having a plurality of configurable building blocks (CBB'"'"'s) wherein each CBB has:

(0.1) a first plurality of input-term acquiring lines for acquiring a preselected subset of input signals from an adjacent set of longer lines that supply signals;

(0.2) a configurable decoding section that is programmably configurable at least into a transparent decoding mode and a multiplexer-emulating mode;

(0.3) a plurality of lookup tables (LUT'"'"'s) where each LUT has at least three address inputs and a corresponding LUT output, where the at least three address inputs of each LUT receive a corresponding, at least three address input signals from a same-numbered and corresponding subset of the input-term acquiring lines when the transparent decoding mode is in effect, and where less than all of the corresponding input-term acquiring lines supply respective input signals to the at least three address inputs of each of two LUT'"'"'s when the multiplexer-emulating mode is in effect; and

(0.4) a dynamically-controllable first multiplexer capable of dynamically selecting for output a selected one of at least two respective LUT outputs from at least a first and second of said plural LUT'"'"'s, the dynamically-controllable first multiplexer being programmably-couplable to receiving a dynamic selection signal from a remainder of said less than all of the corresponding input-term acquiring lines when the multiplexer-emulating mode is in effect,

said method comprising the steps of;

(a) configuring a first of said CBB'"'"'s to emulate a respective dynamically-controllable second multiplexer having at least two dynamically-controllable select terminals and at least four data input terminals; and

(b) configuring a second of said CBB'"'"'s to emulate a respective dynamically-controllable third multiplexer having at least two dynamically-controllable select terminals and at least four data input terminals.

76. The method of claim 75 wherein said first plurality of input-term acquiring lines of each respective CBB consist of a number of such input-term acquiring lines matching the total number of address inputs of said LUT'"'"'s within the respective CBB.

77. The method of claim 76 wherein said total number of address inputs of said LUT'"'"'s within the respective CBB is six.

78. The method of claim 75 further comprising the step of:

(c) coupling at least one of the dynamically-controllable select terminals of the second multiplexer and at least one of the dynamically-controllable select terminals of the third multiplexer to respond to a same select signal.

79. The method of claim 78 further comprising the steps of:

(d) configuring a third of said CBB'"'"'s to emulate a respective dynamically-controllable fourth multiplexer having at least two dynamically-controllable select terminals and at least four data input terminals; and

(e) coupling at least one of the dynamically-controllable select terminals of the fourth multiplexer to respond to the same select signal as that responded to by the dynamically-controllable select terminals of the second and third multiplexers.

80. The method of claim 79 further comprising the steps of:

(d) configuring a fourth of said CBB'"'"'s to emulate a respective dynamically-controllable fifth multiplexer having at least two dynamically-controllable select terminals and at least four data input terminals; and

(e) coupling at least three of the data input terminals of the fifth multiplexer to receive signals respectively output by the dynamically-controllable, second, third and fourth multiplexers.

81. The method of claim 80 wherein:

(1.0) said first through fourth CBB'"'"'s are disposed in one of repeated Variable Grain Block (VGB) structures of the FPGA;

(1.1) each VGB structure further includes at least three feedback lines (FBL'"'"'s) extending continuously only within the VGB structure for providing intraconnect to the VGB structure; and

said method comprises the step of;

(e.1) using three of said FBL'"'"'s to respectively couple said three of the data input terminals of the fifth multiplexer to receive signals respectively output by the dynamically-controllable, second, third and fourth multiplexers.

82. The method of claim 75 wherein:

(1.0) said first and second CBB'"'"'s are disposed in one of repeated Variable Grain Block (VGB) structures of the FPGA;

(1.1) each VGB structure further includes a dynamically-controllable fourth multiplexer that is configurable to dynamically select for its output a respective output of one of said first and second CBB'"'"'s; and

said method comprises the step of;

(c) configuring the fourth multiplexer to dynamically select for its output a respective output of one of said first and second CBB'"'"'s.

83. A method for configuring a Field Programmable Gate Array (FPGA) having a repeated pattern of VGB structures, where each VGB structure includes a plurality of configurable building blocks (CBB'"'"'s) and wherein each CBB has:

(0.1) a plurality of input-term acquiring lines for acquiring a preselected subset of input signals from an adjacent set of supplied signals;

(0.2) a configurable decoding section that is programmably configurable at least into a transparent decoding mode and a multiplexer-emulating mode;

(0.3) a plurality of lookup tables (LUT'"'"'s) where each LUT has at least three address inputs and a corresponding LUT output, where the at least three address inputs of each LUT receive a corresponding, at least three address input signals from a same-numbered and corresponding subset of the input-term acquiring lines when the transparent decoding mode is in effect, and where less than all of the corresponding input-term acquiring lines supply respective input signals to the at least three address inputs of each of two LUT'"'"'s when the multiplexer-emulating mode is in effect; and

(0.4) a dynamically-controllable first multiplexer capable of dynamically selecting for output a selected one of at least two respective LUT outputs from at least a first and second of said plural LUT'"'"'s, the dynamically-controllable first multiplexer being programmably-couplable to receiving a dynamic selection signal from a remainder of said less than all of the corresponding input-term acquiring lines when the multiplexer-emulating mode is in effect,

and further wherein

(1.0) each VGB structure further includes a plurality of feedback lines (FBL'"'"'s) extending continuously only within the VGB structure for providing intraconnect to the VGB structure;

said method comprising the steps of;

(a) configuring a first LUT within a given VGB structure to implement a respective dynamically-controllable second multiplexer having at least one dynamically-controllable select terminal and at least two data input terminals such that the second multiplexer is capable of dynamically selecting for output therefrom, a data signal of one of its said at least two data input terminals in response to a select-control signal supplied to its at least one dynamically-controllable select terminal; and

(b) using one of the FBL'"'"'s to couple the output of the dynamically-controllable second multiplexer to a second LUT of the same given VGB.

84. The method of claim 83 further comprising the step of:

(c) configuring said second LUT to perform a comparison function.

91. A field programmable gate array device comprising CBB-interconnecting lines each extending adjacent to a plurality of Configurable Building Blocks (CBB'"'"'s), wherein each CBB has a plurality of Configurable Building Elements (CBE'"'"'s) distributed within that CBB such that the CBE'"'"'s are adjacent to at least a respective subset of plural ones of said CBB-interconnecting lines, wherein each of said CBB-interconnecting lines can provide interconnection between at least four CBB'"'"'s, and further wherein:

(a) each CBE has at least a first user-programmable lookup table (LUT) for generating a respective first CBE function output signal in accordance with a first user-defined lookup function f_a ( ), where f_a ( ) has a first plurality of input terms;

(b) each CBE includes input term acquiring multiplexers for selectively acquiring respective ones of said first plurality of input terms from respectively adjacent CBB-interconnecting lines, the respectively acquired ones of said first plurality of input terms being organized for dedicated consumption by that CBE when a programmably-defined, transparent decoding mode is in effect; and

(c) each CBE of a given CBB further has passing therethrough, a configurable decoding circuit interposed between the input term acquiring multiplexers and the first LUT of that CBE, the decoding circuit being configurable to strap together inputs of plural ones of the LUT'"'"'s of plural CBE'"'"'s when a programmably-defined, decoding mode other than said transparent decoding mode is in effect.

92. The field programmable gate array device of claim 91 wherein:

(d) each given CBB includes a Configurable Sequential Element (CSE) for selectively outputting to CBB-interconnecting lines extending adjacent to the given CBB, either one or more of said CBE function output signals of the CBE'"'"'s within the given CBB, or higher-level function output signals that are synthesized from CBE function output signals.

93. The field programmable gate array device of claim 92 wherein each CSE comprises:

(d.1) a first register to which at least a first of said CBE function output signals can be stored and from which register a stored signal can be output to the CBB-interconnecting lines extending adjacent to the given CBB.

94. The field programmable gate array device of claim 93 wherein each CSE further comprises:

(d.2) a first multiplexer for selectively routing to a respective first data input terminal of the first register either the first of said CBE function output signals or a higher-level function output signal that is synthesized from CBE function output signals.

95. The field programmable gate array device of claim 94 wherein each CSE further comprises:

(d.3) a second multiplexer for selectively bypassing the first register.

96. The field programmable gate array device of claim 93 wherein each CSE further comprises:

(d.2) a second register to which at least a second of said CBE function output signals can be stored and from which register a stored signal can be output to the CBB-interconnecting lines extending adjacent to the given CBB.

97. The field programmable gate array device of claim 96 wherein each CSE further comprises:

(d.3) a first multiplexer for selectively routing to a respective first data input terminal of the first register either the first of said CBE function output signals or a first higher-level function output signal that is synthesized from CBE function output signals; and

(d.4) a second multiplexer for selectively routing to a respective second data input terminal of the second register either the second of said CBE function output signals or a second higher-level function output signal that is synthesized from CBE function output signals.

98. The field programmable gate array device of claim 91 wherein:

at least a first and second of the CBB'"'"'s are arranged in mirror opposition to one another and wedged-together such that CBB-interconnecting lines are not interposed between the wedged-together first and second CBB'"'"'s;

a sharing area is provided between the wedged-together first and second CBB'"'"'s; and

one or more, shared signal drivers is provided and coupled through the sharing area to the first and second CBB'"'"'s for driving onto neighboring CBB-interconnecting lines, either one or more of said CBE function output signals of the wedged-together CBB'"'"'s, or higher-level function output signals that are synthesized from CBE function output signals.

99. The field programmable gate array device of claim 98 wherein:

resource folding means are provided and coupled through the sharing area for folding together resources found within the mirror-opposed and wedged together CBB'"'"'s.

100. The field programmable gate array device of claim 98 wherein:

(e) each CBE further includes control input acquiring multiplexers for selectively acquiring respective control signals from respectively adjacent CBB-interconnecting lines, the respectively acquired ones of said control signals being programmably routable, at least to Configurable Sequential Elements of the CBB'"'"'s that contain the corresponding CBE'"'"'s.

101. The field programmable gate array device of claim 100 wherein:

(d.1) each Configurable Sequential Element includes at least one register that is controllable by said programmably routable, control signals.

102. A Field Programmable Gate Array (FPGA) device comprising:

(a) a plurality of essentially equivalent, variable grain blocks (VGB'"'"'s) provided adjacent to signal interconnect lines,

(b) wherein each VGB has a plurality of configurable building elements (CBE'"'"'s) with each CBE comprising;

(b.1) acquiring means for acquiring signals from adjacent interconnect lines; and

(b.2) a configurable lookup table (LUT), there being at least four CBE'"'"'s in each VGB,

(c) wherein one or more of the signal acquiring resources or LUT'"'"'s of respective pairs of CBE'"'"'s are combinable to provide larger capability resources in the form of configurable building blocks (CBB'"'"'s), where each CBB comprises;

(c.1) at least two CBE'"'"'s; and

(c.2) a CSE (Configurable Sequential Element) having configurable routing means for routing a desired one of plural outputs of respective ones of said LUT'"'"'s to the interconnect lines,

(d) wherein resources in pairs of CBB'"'"'s can be folded together to provide larger capability resources in the form of sets of paired-CBB'"'"'s, and

(e) wherein resources in quadruples of CBB'"'"'s can be folded together to provide larger capability resources in the form of sets of quadrupled-CBB'"'"'s.

103. A method for configuring a Field Programmable Gate Array (FPGA) device to implement an original circuit design that has been partitioned into plural chunks of different sizes, wherein the FPGA device comprises:

a plurality of variable grain blocks (VGB'"'"'s) provided adjacent to signal interconnect lines,

wherein each VGB has a plurality of configurable building elements (CBE'"'"'s) with each CBE comprising acquiring means for acquiring signals from adjacent interconnect lines and a configurable lookup table (LUT), there being at least four essentially equivalent CBE'"'"'s in each VGB,

wherein one or more of the signal acquiring resources or LUT'"'"'s of respective pairs of CBE'"'"'s are combinable to provide larger capability resources in the form of configurable building blocks (CBB'"'"'s), where each CBB comprises at least two CBE'"'"'s,

wherein resources in pairs of CBB'"'"'s are combinable to provide larger capability resources in the form of sets of paired-CBB'"'"'s, and

wherein resources in quadruples of CBB'"'"'s are combinable to provide larger capability resources in the form of sets of quadrupled-CBB'"'"'s;

said method comprising the steps of;

(a) for each given one of the differently sized chunks, choosing a smallest nonconsumed member in the progressively, more-coarsely granulated entity group consisting of said CBE'"'"'s, CBB'"'"'s, sets of paired-CBB'"'"'s, and sets of quadrupled-CBB'"'"'s that can accommodate the given chunk; and

(b) placing each given chunk in a correspondingly chosen one of said CBE'"'"'s, CBB'"'"'s, sets of paired-CBB'"'"'s, and sets of quadrupled-CBB'"'"'s.

104. The configuring method of claim 103 wherein said lookup table of each CBE (Configurable Building Element) is a 3-input LUT, wherein each CBB (Configurable Building Block) includes a CSE (Configurable Sequential Element) having configurable routing means for routing a desired one of plural outputs of plural 3-input LUT'"'"'s to the interconnect lines, and wherein said method further comprises the step of:

(c) if a given chunk can be fully implemented by a 3-input LUT, configuring said routing means to route as an output of a corresponding 3-input LUT, the respective output of the given chunk.

105. The configuring method of claim 104 wherein said configurable routing means is further for routing a desired one of plural outputs of combined CBE'"'"'s to the interconnect lines, and wherein said method further comprises the step of:

(d) if a given chunk cannot be fully implemented by a 3-input LUT, configuring said routing means to route as an output of a corresponding set of combined CBE'"'"'s, the respective output of the given chunk.

106. A field programmable gate array (FPGA) device comprising a plurality of Configurable Building Blocks (CBB'"'"'s) and a plural number, L of interconnect lines extending adjacent to the CBB'"'"'s, wherein each CBB includes:

(a) a signal acquisition section having a first plurality, N of input multiplexers where N is less than L, said N input multiplexers being configurable for acquiring, from a subset of said L interconnect lines that are adjacent to that CBB, a respective first plurality of N input term signals;

(b) a function spawning section having a second plurality, M of lookup tables (LUT'"'"'s), wherein each of the M LUT'"'"'s is a function spawning LUT that can be configurably coupled to receive a respective subset of N/M input term signals from a respective N/M subset of the first plurality of N input term signals and to responsively produce a respective first level function signal, and further wherein the second plurality of M spawning LUT'"'"'s have a at least N/M respective input terminals for consuming a respective and dedicated subset of N/M ones of the acquired plurality of N input term signals;

(c) a configurable decoding circuit interposed between said signal acquisition section and said function spawning section, the decoding circuit having configurable strapping elements for providing;

(c.1) a first configurable mode in which acquired input term signals are passed transparently as respective and mutually exclusive subsets of N/M ones of the N input term signals from the signal acquisition section to respective LUT'"'"'s of the function spawning section; and

(c.2) a second configurable mode in which a subset of acquired input terms are shared by plural LUT'"'"'s of the function spawning section; and

(d) a function synthesizing section which is configurable to receive at least one of the N input term signals from the signal acquisition section and to use the at least one input term signal for folding together functions of at least two function spawning LUT'"'"'s.

107. The FPGA device of claim 106 wherein each CBB further includes:

(e) a CSE (Configurable Sequential Element) having configurable routing means for selectively routing desired ones of plural outputs of respective ones of said function spawning LUT'"'"'s or a folded together output of the function synthesizing section to corresponding interconnect lines.

108. A machine-implemented method for configuring a Field Programmable Gate Array (FPGA) device to implement an original circuit design that has been partitioned into plural chunks, wherein the FPGA device comprises:

interconnect lines;

a plurality of configurable building elements (CBE'"'"'s), wherein each CBE contains a configurable lookup table (LUT) and a configurable signal-acquiring circuit for pro-grammably acquiring a subset of LUT input terms from adjacent interconnect lines; and

configurable resource folding means for selectively folding together or not, the LUT or signal-acquiring resources of two or more CBE'"'"'s;

said machine-implemented method comprising the steps of;

(a) choosing a given chunk for placement across at least a first of said CBE'"'"'s;

(b) determining if the chosen chunk is too large to entirely fit into the first CBE; and

(c) if said determining step determines that the chosen chunk is too large, configuring said resource folding means to fold resources of an additional one or more CBE'"'"'s together with resources of the first CBE so as to accommodate the chosen chunk.

109. The FPGA configuring method of claim 108 wherein:

(b.1) said step of determining if the chosen chunk is too large includes determining if the chosen chunk has more inputs than are acquirable by the signal-acquiring circuit of the first CBE; and

(c.1) if said determining step determines that the chosen chunk has too many inputs, said configuring step includes configuring said resource folding means to fold the signal-acquiring resources of an additional one or more CBE'"'"'s together with the signal-acquiring resources of the first CBE so as to accommodate the signal input needs of the chosen chunk.

110. The FPGA configuring method of claim 108 wherein said CBE'"'"'s are essentially substitutable, one for the other, for implementing at least a portion of a chunk;

and said machine-implemented method comprises the additional steps of;

(d) deciding if a particular input term signal is routed to move along a given adjacent interconnect line (AIL) so as to be immediately acquirable therefrom by one CBE but not by a second CBE, where the particular input term signal is required by a corresponding, to-be-implemented circuit chunk; and

(e) placing at least the portion of the to-be-implemented circuit chunk that requires the particular input term signal in the one CBE.

111. The FPGA configuring method of claim 110 wherein said placing step includes interchanging the placement of corresponding circuit chunks in the one and second CBE'"'"'s.

112. The FPGA configuring method of claim 110 wherein said given adjacent interconnect line (AIL) is a local interconnect line dedicated to a local subset of CBE'"'"'s.